The present invention relates generally to editing graphics in a pointer based computer system. More particularly, a graphics editor user interface is described.
The use and popularity of pointer based computer systems, including pen-based, stylus-based, track ball, and mouse driven systems has been increasing dramatically in recent years. This increased popularity is typically attributed to the ease of use of such machines, when compared to traditional computing systems that utilize only a keyboard as an input device.
A pen-based computer system is a small, often hand held, computer system in which the primary method for inputting data includes a stylus or "pen". A typical pen-based computer system is housed in a generally rectangular enclosure, and has a dual-function display assembly providing a viewing screen along one of the planar sides of the enclosure. The dual-function display assembly serves as both an input device and an output device. When operating as an input device, the display assembly senses the position of the tip of the stylus on the viewing screen and provides positional information to the computer's central processing unit (CPU). Some display assemblies can also sense the pressure of the stylus on the screen to provide further information to the CPU. When operating as an output device, the display assembly presents computer-generated images on the screen.
The dual-function display assembly of a pen-based computer system permits users to operate the computer as a computerized notepad. For example, graphical images can be input into the pen-based computer by merely moving the stylus on the surface of the screen. As the CPU senses the position and movement of the stylus, it generates a corresponding image on the screen to create the illusion that the stylus is drawing the image directly upon the screen. With suitable recognition software, text and numeric information can also be entered into the penbased computer system in a similar fashion.
Besides serving as a notepad, pen-based computers can provide a number of useful functions, such as serving as an address book, an appointment calendar, a to-do list, etc. These functions can be tightly integrated with the operating system of the computer, permitting information input into one function to impact upon another function.
Users of pointer and pen based computer systems often want to be able to edit graphical objects that are displayed on the screen. It is therefore desirable that a readily usable user interface be provided to facilitate the editing of graphics.